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Ortofon A-90 Tonality Question

I got an A-90 about two weeks ago to replace a Koetsu RSP. I have it dialed in as best as possible and find that it does almost everything well in my system. I have the cartridge body level in terms of SRA, VTF is 2.2 grams and azimuth was measured with a DMM/test record.

The problem I am having is a leanness in the midrange, especially on vocals. There is a bit more sibilance than I would expect and there is a lack of richness in the lower vocal registers.

This may be that I am used to the Koetsu sound but based on observations here and on AA this doesn't seem to be a general issue and it seems more pronounced than I would expect.

Associated equipment is VPI HR-X/JMW 12.5 with Discovery wire (run from cartridge clips and soldered to phono stage input), Herron VTPH-2 phono stage, very modified Cary SLI-80 amp and Merlin TSM-MMi speakers. Interconnects are VH labs DIY silver and speaker cables are VH Labs Chela.

Based on general specifications the JMW arm should match fairly well to the A-90 but the A-90 performance seems to have some tonearm dependence. Also, there are only about 25 hours on the A-90 so it change over time.

Anyone running an A-90 in a VPI arm or have similar results in other setups?
jarrett
jarrett OP
38 posts
 
Thanks for the responses. I have tried impedances ranging from infinite load(Herron VTPH-2 has this option), 47k, 2400, 850 and now 120 ohms. 120 ohms sounds best at present.

One thing I completely forgot about was when I made some major changes to my system recently I started using a Venhaus DIY silver wire interconnect in place of the Discovery Essence I had sold previously.

I never had the Venhaus IC in my old system and my prior experience with all-silver IC's was to my ear they sounded bright. I pulled out an awful generic copper IC I has laying around and although the overall sound is poor it definitley got rid of the sibilance.

I agree the cartridge will gradually smooth out itself over time but now I need to locate a suitable IC replacement for the Venhaus. it's a shame as the Venhaus does everything very well except the tilted up tonal balance.
downunder
1,329 posts
 
The A90 sounds just like what is it is being fed.

I owned the HRX for about 4 years and could never get rid of the slight leanness in the midrange, leading edge in the upper mids and lack of richness compared to my TNT V-HR.

Your Koetsu has been balancing that sonic trait IMO.

The guys are right, the A90 will breath better with more hours, however I don't think it will change that much, hopefully I am wrong.

If it does not improve, you might need to look at changing cartridges to a tonally richer sounding one, or change your turntable like I did.
jarrett OP
38 posts
 
I also thought it might be the JMW arm although on paper the specs seem to fit.

The Reed arm might be a good replacement if I decided to go that direction.
lasercd
50 posts
 
I spent two evenings comparing 47 and 100 ohms impedance settings on my ASR Basis Exclusiv. I even enlisted a second pair of ears. We agreed that 47 ohms was clearly and constantly preferred to 100 ohms. At 100 ohms everything sounded washed out, even with adjustments to VTA. Strings were steely and bass was diminished. 47 ohms just sounded more dynamic, strings were silky, bass lines "popped" - it was just a richer sound. It sounded right.

You might want to spend some more time experimenting with a lower impedance setting. I know other people have had success at 100 ohms so I guess its system dependent. Worth exploring more in my opinion.

Ken Golden
wrm57
1,040 posts
 
I like mine at 50 ohms, too, through my Maxxed-Out.
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